Update #1
The problem appears to be confined to recent versions of the Chrome browser and is platform dependent, i.e. it works on some systems but not on others. Hopefully this issue will soon be resolved in newer releases of Chrome.
Meanwhile, if you are experiencing this issue in Windows for example and don't want to switch browsers, you could install the Chrome plug-in extension "IE Tab". This enables Zinepal to function correctly (in Windows IE mode) within Chrome. I have tested this particular workaround successfully.
Paul.